isotope

            flat.portfolio_isotope = $('.portfolio-isotope');
            flat.portfolio_menu = $('.isotope-menu li');
            flat.portfolio_isotope.isotope({
                itemSelector: '.single-portfolio',
                layoutMode: 'fitRows'
            });

            flat.portfolio_menu.on('click', function () {
                flat.portfolio_menu.removeClass("active");
                $(this).addClass("active");
                var selector = $(this).attr('data-filter');
                flat.portfolio_isotope.isotope({
                    filter: selector,
                    animationOptions: {
                        duration: 750,
                        easing: 'linear',
                        queue: false,
                    }
                });
                return false;
            });